Ore-roasting furnace



No. 625,336. Patented May 23, |899. J. F. KEIPER. 4

ORE BOASTING FUBNACE.

(Application led May 17, 189B.) (No Model.) 2 Sheets-Sheet I.

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no. 625,336. I Patented may 23, |899.

J. F. KEIPER.

URE ROASTING FUBIIACE.

(Application led May 17, 1898.) @No Model.) 2 Sheets-Sheet 2.

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NiTnD STATES PATENT OFFICE.

JOHN F. KEIPER, OF EVERETT, WASHINGTON.

ORE-ROASTING FU RNACE.

SPECIFICATION forming part of Letters Patent No. 625,336, dated May 23,1899.

Application led May 17, 1898.

To @ZZ 'whom t ntrry concern:

Be it known that I, JOHN F. KEIPER, a citizen of the United States,residing at Everett, in the county of Snohomish and State of Washington,have invented a new and useful Ore-Roasting Furnace, of which thefollowing is a specication.

My invention relates to ore roasting and calcining furnaces designedparticularly for use in the treatment of sulfurous and arsenical ores;and thel object in view is to provide means for accomplishing a uniformheating or roast-ing of the ore, a more uniform distribution thereofover the surface of the hearth, and greater facility in depositingtheore upon the hearth and in discharging the same therefrom whensufficiently roasted.

A further object of myinvention is to provide means whereby as theroasting operation proceeds the ore is gradually advanced from the pointat which it is deposited upon the hearth to an outlet located at a pointwhich is radially remote from the point of deposit.

Further objects and advantages of this invention will appear in thefollowing description, and the novel features thereof will beparticularly pointed out in the appended claims. v

In the drawings, Figure 1 is a central vertical section of a furnaceconstructed in accordance with my invention, the same being taken in theplane of the rabble. Fig. 2 is a plan view of the furnace with the domedtop omitted. Fig. 3 is a partial side view to show the exterior means,located contiguous to the discharge-chute, for operating the rabble.Fig. i is a detail sectional view of the hearth and contiguous portionsof the structure to show the means for sealing the joint for closing theinterval between the periphery of the hearth and the wall of thefurnace. Fig. 5 is a detail view in perspective of a portion of therabble.

Similar numerals of reference indicate corresponding parts in all thefigures of the drawings.

My invention relates to that class of oreroasting furnaces wherein theore is deposited upon a circular or annular hearth; and that embodimentof my invention which I have deemed best adapted to carry out the SerialNo.680,942. (No model.)

objects in View includes an annular furnace wall l, having a domed topor cover 2, provided with an ore-inlet opening 3, with whichcommunicates a feed -hopper 4, said feedopening being located adjacentto the center of the domed top or cover, where a working opening 36 isprovided to give access to the interior of the furnace.

Ooextensive with the furnace and mounted for revoluble movement thereinisa circular hearth 6, which in the construction illustrated is providedwith a refractory ore-receiving surface 7, of brick or analogousmaterial, supported by metal plates 8, which are in turn u pheld byframe-bars consisting of' I- rails 9. The illustrated refractory surfaceof the hearth is of stepped construction, consisting of a series ofannular steps or platforms which are arranged in successively-lowerplanes from the center of the hearth toward its periphery. It will beunderstood, however, that the object in arranging the steps or platformssuccessively lower from the center toward the periphery is to allow fora gradual descent of the ore from the point of inlet or deposit to'the'point of outlet or discharge. In the furnace which is illustratedthe hopper or inlet opening is disposed to discharge ore upon theuppermost or central step or platform of the hearth, while located inthe wall of the furnace, and hence beyond the periphery of the hearth,and in and below the plane of the lower-most peripheral step or platformis a discharge-chute 10, extending in a downwardly and outwardlyinclined di-A rection through the furnace-wall to convey theproperly-roasted contents of the furnace to a point outside of the same.

The hearth, as above indicated, is constructed for rotary movement, andsuch movement is designed to bring different portions of its surfacesuccessively on a line connecting a fire-box or combustion-chamber 13and the outlet-fine 14, said hre-box and outlet being preferably locatedat diametrically opposite points and communicating with the interior ofthe furnace, and the means illustrated in the drawings for supportingthe hearth in= cludea central spindle l5, extending above and below theplane of the hearth, with the lower extremity seated in a socket-bearing16,- supported by a pedestal, base, or foundation ICO 17. Also attachedto the under sides of the radial frame-bars 9 of the hearth isa circulartrack-rail 18, which traverses a plurality of bearing-rollers 19, eachsuitably mounted upon a base 20.

Various means may be provided for imparting continuous rotary motion tothe hearth; but in the drawings I have deemed it suliicient toillustrate a cable 21 or its equivalent (such as a chain) traversingspaced brackets or sprockets 22, depending from the under side of thehearth and adapted to be actuated by any suitable means.

The upper portion of the spindle 15 may be inclosed in a suitablerefractory sheath 15, and seated upon the upper end of said ,spindle isa cap 23, an antifriction-bearing 24, consisting of balls or rollers,being interposed between the cap and the extremity of the spindle, andmounted at their inner ends in bearings 25, carried by said cap, arerabblespindles 26, preferably of tubular construction and extendingradially of the hearth above the plane thereof and through suitableguides orapertures 27 in the side walls of the furnace. The outer endsof the rabble spindles or shafts are fitted with operating-levers orhandles 2S.

The rabble-shafts, of which any desired number may be employed, occupyiixed p0- sitions with relation to the furnace and carry a series ofrabble or stirring blades 31, disposed at an angle to the radius of thehearth, the blades of the diderent rabble-shafts being inclined indiiferent directions to cause a backward-and-forward or radialinward-andoutward shifting of the ore on the surfaces of thehearth-steps. Obviously the ultimate result of this shifting of the oreby the blades is to advance it radially from the point of the depositthereof to the point of discharge, whereby inasmuch as one of therabbleshafts is located contiguous to the discharge-chute 10 apractically continuous discharge of the ore through the chute after ithas passed through the distance from the hopper to the periphery willresult after the operation of the mechanism has continued for asufficient length of time to cover the entire surface of the hearth.Furthermore, in order to prevent the access of cold air to the spaceabove the hearth I employ a packing device consisting of a rim 39,secured to the outer ends of the I-rails 9 and depending from the outeredge of the refractory surface of the hearth, and an annular trough,groove, or analogous receptacle 40, lled with sand, iine ore, or anyequi valent granular or movable packing material 41 and receiving thelower edge of said rim. This form of packing does not interfere with therotary movement of the hearth, and yet is effective in preventing wasteof the heat.

The advantage of my present form of hearth resides in the fact that thedischarge,`after the furnace has beenworking a sufficient length of timeto secure a uniform distribution of ore upon its surface, is continuous,and hence the supply may also be continuous and insure a uniformity inthe roasting 0peration, which is desirable in this class of devices.

Various changes in the form, proportion,

Aand the minor details of construction may be resorted to withoutdeparting from the spirit or sacrificing any of the advantages of thisinvention.

Having described my invention, what I claim is- 1. An orc-roastingfurnace having arotary stepped hearth, means for depositing materialupon, and receiving the same after the roast# ing operation from, thehearth, and a feeding device for advancing the material upon the hearthfrom the point of deposit to the point of discharge, said meansconsisting of a series of blades, disposed diagonally with relation to aradial line of the hearth, and in operative relation with the severalsteps of the hearth-surface, and a radial spindle,- supporting aplurality of said blades, mounted for revoluble movement to provide forswinging the blades toward and from the surface of the hearth,substantially as specified.

2. An ore-roasting furnace having a rotary stepped hearth, means fordepositing material upon, and receiving the same after the roastingoperation from, the hearth, and a feeding device for advancing thematerial upon the hearth from the point of deposit to the point ofdischarge, said device consisting of a series of blades disposedobliquely to a radial line of the hearth and in operative relation withthe several steps of the hearth-surface, and a spindle common to andsupporting the series of blades, mounted for revoluble movement towithdraw said blades from operative relation with the surface of thehearth, and provided with means, located outside of the furnace-wall,for varying the position of said spindle, substantially as specified.

3. An ore-roasting furnace having a rotary stepped hearth, means fordepositing material upon, and receiving the same, after the roast-l ingoperation, from, the hearth, and a feeding device, for advancing thematerial upon the hearth from the point of deposit to the point ofdischarge, said means including a series of diagonally-disposed bladesarranged in operative relation with the several steps of thehearth-surface, and a common blade-supporting spindle mounted in fixedbearings in the furnace,and terminally exposed for manipulationexteriorly thereof, substantially as specied.

4. An ore-roasting furnace having a rotary IOO IIO

hearth stepped downwardly from its center per exposed extremity of thehearth-spindle, a refractory sheath inclosing.,r the portion of thehearth-spindle below said cap, and bladecarrying spindles mounted neartheir outer ends in the Walls of the furnace and at their inner ends inbearings in said cap, substantially as specied. A

5. An ore-roasting furnace having a domed top provided with a centralWorking hole having a removable stopper, a rotary stepped hearth having'a central spindle arranged in alinement with said working hole andstepped at its lower end in a suitable bearing, said hearthbeingelevated at its center andV depressedat its periphery, oredepositing and .the presence of two Witnesses.

JOHN F. KEIPER.

Witnesses: Y

LoUIs G. HEYBRQCK, ALBERT A. BRoDEoK.

